1. Field of the Invention
The present invention relates to an analog-to-digital converter and, more particularly, to a sequential comparison-type analog-to-digital converter.
2. Description of the Related Art
In the prior art, a plurality of analog-to-digital converters (AD converters: ADCs) mounted on, for example, microcomputers and system LSIs are those of the sequential comparison type from the standpoint of decreasing the sizes yet maintaining high precision.
Sequential comparison registers and control logic circuits, DA converters and sequential comparison-type AD converters equipped with a comparator have heretofore been disclosed in a variety of documents such as Sagara Iwao, “Introduction to A/D•D/A Converters (2nd Edition)”, Nikkan Kogyo Shimbunsha, Mar. 31, 2003, pp. 116-117; Yoshinaga Jun (supervised by Shoda Eisuke), “Alte-21 Analog Circuit”, Ohm Co., Jun. 25, 1998, pp. 111-114; D. Johns et al, “ANALOG INTEGRATED CIRCUIT DESIGN”, John Wiley & Sons, Inc., 1997, pp. 492-493, etc.
The prior art and its associated problems will be described in detail later with reference to accompanying drawings.